The invention is directed to landscape edging used as a barrier between landscaped areas of different composition.
Landscape edging is now commonly used to divide different landscape areas to preclude one area from spilling or growing into an adjacent area For example, landscape edging is effectively used as a divider between grass and a flower bed to prevent the grass from taking root in the flower bed, and also to prevent bedding material in the flower bed from spilling into the grass.
In the past, landscape edging has been formed from lengths of wood or corrugated metal strips and such materials have served reasonably adequately. However, wood decays over a period of time, and metal has a tendency to rust, corrode, or to become bent and misshapen over time. Consequently, the most prevalent materials used for landscape edging today are inert synthetic plastics such as polyethylene and ethylene vinyl acetate. These materials are generally flexible and are therefore easily installed, while at the same time having an extended life expectancy that avoids the necessity of replacement at frequent intervals.
Although landscape edging formed from inert synthetic materials provides a better product because deterioration is avoided, problems nevertheless occur due to the environment in which the landscape edging is installed. More specifically, conventional edging normally consists of a longitudinally extending strip of material having a lower edge that is inserted into the ground to a predetermined depth, and an upper edge or rall that generally projects above the ground. The edging is typically installed by digging a narrow trench, inserting the lower edge to a predetermined depth, refilling the trench and compacting the earth around the edging. Such installation normally maintains the edging in its intended position for a period of time. However, the environment in which the landscape edging is placed usually-works against its remaining in place over extended periods of time. More specifically, the edging may be walked on, bumped, kicked or otherwise engaged, and repeatedly driven over by lawn mowers or lawn tractors.
Equally severe to the integrity and placement of landscape edging is freezing of the ground at and below the level of the edging during the winter months. The ground retains moisture in the fall, which freezes with dropping temperatures. Water is one of few materials having a coefficient of volume expansion that increases as temperature decreases, and the ground accordingly expands with frozen moisture in the winter. This has the effect of compressing the landscape edging, which can cause it to break as well as to become displaced.
As temperatures rise, the moisture beneath the ground surface melts, again changing the subsurface ground composition. As these seasonal temperature changes alternate, the landscape edging is repeatedly exposed to a variety of forces that, over the long term, cause it to become dislodged and/or damaged.
This invention is a result of an endeavor to design landscape edging that is no more complex from the structural standpoint than conventional edgings, but which will be initially anchored and remain in a stable position from season to season, thus extending its useful life.
The inventive edging comprises a longitudinally extending body that itself may take various forms, a longitudinal top rail extending along the upper edge of the body, and an anchoring member extending longitudinally along the lower edge of the body. In a preferred embodiment, the top rail is a tubular member of circular cross section that serves as a fluid conduit, permitting the use of various spray and sprinkler devices for watering plants adjacent the edging. The tubular member also assists to some extent in anchoring the upper edge above the surface of the ground by its rigidity and resistance to being bent over and broken, which is typically with edgings have straight top edges.
The tubular top rail of the primary embodiment is opaque, but in an alternative embodiment the top rail may be wholly or partially transparent, permitting the use of a low voltage conductor and a series of lights for use along walkways.
A primary feature of the invention resides in the anchoring member, which in the preferred embodiment takes the form of an inverted, hollow triangle that extends along the lower edge of the body. The inverted triangle is symmetrically disposed relative to the body, so that equal portions project laterally from the opposed faces of the body. Two of the triangular legs converge into a downwardly projecting central point that extends directly below the edging body.
The inventive edging is conventionally installed. A trench is dug, and the edging is inserted into the trench with the anchoring member pointed downward. As the dirt is refilled and compacted around the edging body, it surrounds the anchoring member. The laterally projecting portions of the triangular anchor resist upward movement of the edging, particularly during the winter sub-surface freeze, and the symmetry of the projecting member resists lateral movement. As such, the landscape edging is strongly anchored, maintaining its structural integrity and remaining stationary over extended periods of time.
A series of additional embodiments include a modification to the triangular anchoring member that addresses and solves a common problem encountered in packaging landscape edging. More specifically, the relatively large top rail and anchoring member are of considerable importance in overcoming the problem of season-to-season instability of the edging as described above. However, the cross-sectional profile of such an edging creates some degree of difficulty in packaging the edging for distribution and sale. Landscape edging is most commonly packaged in a coil, although it is sometimes packaged in a plurality of lengths. In either case, the irregular cross-sectional profile of virtually all landscape edging is inherently problematic in attempting to maintain the material in a compact coil, and the problem is compounded with the relatively large circular top rail and relatively large triangular anchoring member. This profile does not lend itself to coil or strip packaging that relies on a stable interrelationship between adjacent portions of the edging.
In view of this, the customary approach to packaging landscape edging is in coils of predetermined length that are sheathed in cardboard (e.g., boxes that are open on one or two ends). This is a suitable solution to the problem but a relatively expensive one, requiring not only the materials in creating the cardboard sheath or box but labor as well in handling each coil and placing it in the box.
Tying the formed coil at a plurality of points would be far less expensive from both the standpoints of materials and labor, but for the reasons discussed above the instability of the coil does not lend itself to such packaging.
The alternative embodiments of the invention permit the landscape edging to be at least partially retained in a packaged position (e.g., in a coil or adjacent strips), and hence to be tied or wound at a plurality of points, resulting in a package that is smaller, tighter and more easily handled. This is accomplished by forming an anchor member having a transverse dimension that is at least as wide as the top rail member, providing a longitudinal tongue along one side of the anchor member and a longitudinal groove that mates with the tongue on the opposite side of the anchor member. While it is within the scope of the invention to construct the tongue and groove in a manner which will cause them to interlock (e.g., a dovetail configuration that results in a snap fit), it is essential only that the tongue fit into the groove. This enables a finite length of the edging to be coiled, by machine or by hand, with the tongue and groove in mateable engagement, followed by tying the coil at a plurality of points. Each one of the ties forces the longitudinal tongue into the corresponding groove, resulting in coil stability. A tying clip may also be used with the tie that transversely overlies the top rails in the area of tying, providing additional stability to the packaged coil.
This improvement results in an edging package that is less expensive to accomplish, much more stable than conventional edging packaging and much easier to handle during transportation, distribution and sale.